Paint Worm vs Missing Digits

Paint Worm is a minimalist puzzle game where you guide a worm across a grid, painting every cell exactly once before escaping through the exit. HOW TO PLAY Move the worm using arrow keys (or on-screen D-pad). Your goal is simple: paint every paintable cell on the board, then reach the exit. The catch — you can never revisit a painted cell, and running into a wall too long ends your run. FEATURES • 370 handcrafted stages across 13 grid sizes — from relaxed 6×7 grids to demanding 14×18 puzzles • Smooth difficulty curve from beginner to expert • Full keyboard support — play entirely with arrow keys on Mac • 4 color themes: Mint, Berry, Sunny, Ocean • Dark mode support • Haptic feedback on mobile • Background music with toggle A pure logic puzzle. No timers, no ads interrupting gameplay, no in-app purchases. Just you and the grid.

Uncover the hidden digits by reasoning, not guessing. 4■2 + ■8■ = 12■5. Guessing gets you nowhere. But follow the carry from the ones column, and the answer narrows to exactly one possibility. FUKUMEN does one thing: missing-digit arithmetic, done beautifully, forever. ■ Features - Endless puzzles, generated on your device From simple addition to full long multiplication with three partial-product rows. You will not see the same puzzle twice. - Exactly one answer, always Each puzzle starts as a completed sum, then digits are hidden — but only up to the point where a second answer would become possible. Every puzzle is verified before it reaches you. No unsolvable boards. No ambiguous boards. - Four difficulties Easy and Normal are addition. Hard and Oni are long multiplication. At Oni, 19 of the 26 cells are blank. - Today's puzzle One puzzle a day, the same one for everyone. Streaks and a calendar keep your history visible. - A real long-form layout Chalk on a blackboard, set vertically the way you'd write it by hand. Tap a blank, type a digit. The board scales up when the numbers are short. - Quiet help Columns that can't work out are tinted, gently — you can turn this off. And if you're truly stuck, a hint opens a single cell. - Records Puzzles solved, streak, average time, best time per difficulty. ■ Who it's for - Sudoku and crossword solvers looking for something that actually uses arithmetic - Anyone who wants to deduce rather than drill - Parents and kids working through missing-digit problems for entrance exams - People building a small daily thinking habit - Anyone who needs a puzzle that works with no signal — trains, planes, anywhere